/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.zookeeper.server.auth;

import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.server.ServerCnxn;

public class SASLAuthenticationProvider implements AuthenticationProvider {

	public String getScheme() {
		return "sasl";
	}

	public KeeperException.Code handleAuthentication(ServerCnxn cnxn, byte[] authData) {
		// Should never call this: SASL authentication is negotiated at session
		// initiation.
		// TODO: consider substituting current implementation of direct ClientCnxn
		// manipulation with
		// a call to this method (SASLAuthenticationProvider:handleAuthentication()) at
		// session initiation.
		return KeeperException.Code.AUTHFAILED;

	}

	public boolean isAuthenticated() {
		return true;
	}

	public boolean isValid(String id) {
		// Since the SASL authenticator will usually be used with Kerberos
		// authentication,
		// it should enforce that these names are valid according to Kerberos's
		// syntax for principals.
		//
		// Use the KerberosName(id) constructor to define validity:
		// if KerberosName(id) throws IllegalArgumentException, then id is invalid.
		// otherwise, it is valid.
		//
		try {
			new KerberosName(id);
			return true;
		} catch (IllegalArgumentException e) {
			return false;
		}
	}

	public boolean matches(String id, String aclExpr) {
		if (System.getProperty("zookeeper.superUser") != null) {
			return (id.equals(System.getProperty("zookeeper.superUser")) || id.equals(aclExpr));
		}
		return (id.equals("super") || id.equals(aclExpr));
	}

}
